test: Add integration coverage for boolean schemas via /gates

Extend the OpenAPI fixture with a /gates endpoint whose request body
uses properties.open: true (any value accepted) and properties.blocked:
false (any presence rejected). Two IT cases verify a body with only
'open' returns 200 and a body containing 'blocked' returns 400 with
keyword "false" in the problem detail.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: thced

src/test/java/com/retailsvc/http/OpenApiServerIT.java

@@ -598,4 +598,51 @@ void postBlockedForbiddenTokenReturns400() {
       }
     }
   }
+
+  @Nested
+  class Gates {
+
+    String path = "/gates";
+
+    @Test
+    void postGateBodyWithOnlyOpenReturns200() {
+      try (var server = newServer(Map.of("post-gate", new EchoHandler()));
+          var client = httpClient()) {
+        var body = "{\"open\":\"anything\"}";
+        var request = newRequest(server, path, "POST", ofString(body));
+
+        var response = client.send(request, BodyHandlers.ofString());
+
+        assertThat(response.statusCode()).isEqualTo(200);
+      } catch (IOException e) {
+        fail(e);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+        fail(e);
+      }
+    }
+
+    @Test
+    void postGateBodyWithBlockedReturns400() {
+      try (var server = newServer(Map.of("post-gate", new EchoHandler()));
+          var client = httpClient()) {
+        // Any value in 'blocked' triggers the false-schema rejection,
+        // because NeverSchema rejects every value.
+        var body = "{\"open\":\"x\",\"blocked\":\"anything\"}";
+        var request = newRequest(server, path, "POST", ofString(body));
+
+        var response = client.send(request, BodyHandlers.ofString());
+
+        assertThat(response.statusCode()).isEqualTo(400);
+        assertThat(response.headers().firstValue("Content-Type").orElse(""))
+            .contains("application/problem+json");
+        assertThat(response.body()).contains("\"keyword\":\"false\"");
+      } catch (IOException e) {
+        fail(e);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+        fail(e);
+      }
+    }
+  }
 }

src/test/resources/openapi.json

@@ -250,6 +250,27 @@
         },
         "responses": { "200": { "description": "OK" } }
       }
+    },
+    "/gates": {
+      "post": {
+        "operationId": "post-gate",
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "required": ["open"],
+                "properties": {
+                  "open": true,
+                  "blocked": false
+                }
+              }
+            }
+          }
+        },
+        "responses": { "200": { "description": "OK" } }
+      }
     }
   },
   "components": {

src/test/resources/openapi.yaml

@@ -177,6 +177,23 @@ paths:
         "200":
           description: OK
 
+  /gates:
+    post:
+      operationId: post-gate
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required: [open]
+              properties:
+                open: true
+                blocked: false
+      responses:
+        "200":
+          description: OK
+
 components:
   parameters:
     Name-Header: